The Impacter is a real-time audio source plug-in intended for use with impact-type sound files. These are files that consist of a short sound with a fast or instantaneous onset and an exponentially decaying envelope. The plug-in allows you to manipulate the source sounds in the following ways:

  • Cross-synthesis: The Impacter separates each source file into an impact component and a body component. The impact component consists of the impulse of the sound while the body component consists of the resonance of the sound. When using the Impacter with a collection of files, the plug-in will randomly combine the impact component of one file with the body component of another file for each play event. The plug-in allows you to individually include or exclude the impact and body components of each file.

  • Physicality manipulation: The Impacter allows you to modify the perceived mass, velocity, position, and roughness of the object creating the impact sound. A randomizing parameter can be assigned to each of these properties, creating sonic variety for each play event.

  • Mapping properties to game physics: Each instance of the plug-in can be associated with a Game Object, Event, or RTPC. The parameters of the Impacter are designed to respond to game engine physics related to materials and collisions.

The authoring tool supports dragging and dropping files into the source editor. All analysis is handled within the authoring plug-in; there is no need for an external analysis tool or an analysis results file. The resulting synthesis model is included in the project’s SoundBanks for use during runtime.


The analysis and synthesis algorithms in the Impacter plug-in work well because they make certain assumptions about the type of sounds they are treating. Specifically, they are designed for short sounds with a fast or instantaneous onset and an exponentially decaying envelope. Some degree of time variance or secondary transients in the decay can be handled, but those characteristics are not as strongly affected by the synthesis parameters.

Other types of sounds can be dropped into the plug-in, but the sonic results may fall outside of the expected behavior when trying to shape the sound using the provided parameters. This may still be a desirable outcome, especially if the Impacter is being used for novel sound design exploration. Longer sounds, however, will extend the length-of-analysis time and may interrupt the authoring tool from playing sound until the analysis is complete.

Was this page helpful?

Need Support?

Questions? Problems? Need more info? Contact us, and we can help!

Visit our Support page

Tell us about your project. We're here to help.

Register your project and we'll help you get started with no strings attached!

Get started with Wwise